If it was a dump of many databases, the use statements are already in there. To run these commands, open up a command prompt (in Windows) and cd to the directory where the mysql.exe executable is (you may have to look around a bit for it, it'll depend on how you installed mysql, i.e. standalone or as part of a package like WAMP).
How do I restore a dump file from mysqldump? - Stack Overflow
In programming, to dump something means to get its content. For example, if one says you need to dump memory at address XY it means to query the content of the memory at the given address and store it somewhere for analysis (the result is then called a memory dump).
The extra step of writing to a string is not needed. dump internally writes in chunks. This could be more efficient than to compile a (possibly huge) string first.
python - How to dump a dict to a JSON file? - Stack Overflow
Really, pg_dump by default should dump everything (options to exclude) and pg_restore should restore exactly whatever pg_dump dumped. And that means everything observable.
If you want to dump the JSON into a file/socket or whatever, then you should go with dump(). If you only need it as a string (for printing, parsing or whatever) then use dumps() (dump string) As mentioned by Antti Haapala in this answer, there are some minor differences on the ensure_ascii behaviour. This is mostly due to how the underlying write() function works, being that it operates on ...
What is the difference between json.dump () and json.dumps () in python?